Rheostat and electric heater



(No Model.)

H. P. BALL.

RHEOSTAT AND ELECTRIC HEATER.

Patented Mar. 1,1898.

UNITED STATES PATENT OFFICE.

HENRY PRICE BALL, OF BROOKLYN, NEW YORK,-ASSIGNOR TO THE WARD LEONARD ELECTRIC COMPANY, or BRONXVILLE, NEW YORK.

RHEOSTAT AND ELECTRIC HEAT-ER.

SPECIFICATION formingpart Of Letters Patent N0. 600,057, dated March 1, 1898.

Application filed October 30, 1897. Serial No. 656,864. (No model.)

To all whom it may concern.-

Be it known that I, HENRY PRICE BALL, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Rheostats, Electric Heaters, and Similar Apparatus, of which the following is a specification.

My invention relates to rheostats, electric IO heaters, and other apparatus in which electric energy'is converted into heat and in which the conductor is attached to a support by means of an adhesive material.

In the construction of electric heaters and rheostats it is almost the universal practice to attach the conductor to the support by means of vitreous material, such as enamel, and heretofore it was the practice to entirely embedthe conductor in the vitreous matezo rial. In such apparatus I have found in practice that ,the rate of expansion of the conductor is considerably greater than the rate of expansion of the vitreous material. This difference in expansion causes the vitreous ma- 2 5 terial to flake or crack and in many instances causes the vitreous material to strip from the support, so as to render the apparatus unfit for use. This difficulty is overcome by my invention, which consists in greatly increasing the radiating-surface of the conductor without increasing the cross-sectional area and in only partially embedding the conductor in the adhesive material. In carrying myinvention into effect I preferably employ a conduc- 3 5 tor in the form of a broad thin strip or ribbon and attach it edgewise to the support. In practicethe ribbon-like conductor is -reflexed, so that a greater length of the conductor maybe conveniently placed withinagiven 0 space, and the refiexing of the ribbon-like conductor makes it self-supportin g on the support during the operation of attaching it to the support by the adhesive material. ranging the conductor in this way the strains 5 caused by expansion are practically eliminated, except strains in a direction parallel to the surface of the support that is, compressive strains. The enamel or equivalent material is capable of withstanding such strains to a considerable extent without rupture, and I have found in practice that the By ar-' conductor when arranged in accordance with my invention may be heated to the meltingpoint without rupturing the enamel or equivalent material. A

In the accompanying drawings various forms are shown for applying my invention to electric heaters and rheostats.

Referring to Figure 1, A is a supportingbody, which may be of metal or other suitable material and of any desired shape. is the reflexed ribbon-like conductor, attached edgewise to the support by one or more layers 0, of vitreous material, such as enamel. The conductor B in practice will be provided withterminals b, adapted to be attached to contact-plates or binding-posts, as is well understood.-

In Fig. 2, A represents a metal support, to

which is applied a coating of insulating material C, commonly called the ground coat, and which coat may be of a vitreous or other suitable material. The conductor B is placed edgewise upon this coating, and then a coating 0 of vitreous material, such as enamel, is applied, and which coating is fused and upon cooling attaches the conductor to the support. s

Fig. 3 represents a support A, made ofinsulating material, such as porcelain or any other suitable insulating material. The conductor Bis placed edgewise upon this support and attached thereto by a layer of vitreous material 0 In Fig. 4 is illustrated a'modification of the form shown in Fig. 3, A beingthe support of insulating material, and B the conductor. In this-form the supporting-body is slotted, as shown, and the conductor placed edgewise in the slot, which is filled on both sides of the conductorwith a layer of vitreous material C and the surface of the support is coated by a layer of vitreous material 0 both layers 0 and G adhesively attaching the con ductor to the support. In this form the layer of vitreous material 0 might be dispensed with and the slot made quite narrow, so that the conductor will fit snugly therein and the layer of vitreous material C be alone employed to hold the conductor in place. This form of support might be made of metal and the walls of the slot insulated and the conlayer of vitreous insulating material between this form the conductoigis attached only at.

intervals to the support instead of throughout its length; as shown in Figs'l to 4, inclusive. With this arrangement the tendency to rap ture the attaching material is further decreased, because the conductor is free to expand in all directions between the points of support without aifecting the attaching maexposed.

ter al.

Figs. 8 and 9 show a further "modification of the feature of attaching at intervals. In this form the conductor is provided with a series of lateral projections, which maybe of any desired shape, and which projections are partially or entirely embedded in the att ach-' ing material, the body of the conductor being In Fig. 10 is illustrated a still further modification of the feature of' attaching the couductor at intervals to the support. In this form the conductor is carried by a series of clips, which are embedded in the attaching material, the conductor itself being entirely exposed except where the clips surround it.

In this structure the clips may be of any de- 'sired form and the conductor may be round,

- asiilustrated, or rectangular, or any other desired shape, the supporting-clips, of course,

- Figs. 5, 6, 7, and

supporting-plates being constructed accordingly.

In all'of the forms illustrated, except Fig. 10, the conductor may be held between two ,as indicated in dotted lines,

' What I claim is i 1. The combination of a ribbon-like con ductor, a supporting-body and a layer of and hesive material by which the conductor is attachedto the support and in which the con-'.

ductor is only partially embedded, substantially as set forth.

2. The combination of a ribbon-like conductor, a supporting-body and a layer of vitreous material by which the conductor is at tached to the support and in which the conductor is only par ially embedded, substantially as set forth. Y

3. The combination of. a ribbon-like con-- ductor, a metal supporting-body, and a layer a of adhesive insulating material between the conductor and support, and by-which the conductor is attached to the support and in which the conductor is only partiallyembedded, substantially as set forth.

4. The combination of a ribbon-like c'onductor, and a metal supporting-body, and a The slotted form of support the conductor and support, and by which the conductor is attached to the support and in which the conductor is only partially embedded, substantially as set forth.

5. The combinationof a ribbon-like conductor, a supporting-body and a layer of adhesive material by which the conductor is 'at-' tached edgewise to the support and in which the conductor is only partially embedded,

substantially as set forth. 7

6. The combination of a ribbon-like conductor, a supporting-body and a layer of vitreous material by which the conductor is attached edgewise to the support andin which the conductor is only partially embedded, substantially as set forth.

'7; The combination of a ribbon-like conductor, a metal supporting-body, and alayer of adhesive insulating material between the conductor and support, and by which the conductor is attached edgewise to the support and in which the conductor is'only partially embedded, substantially as set forth.

8. The combination of a ribbon-like conductor, and a metal supporting-body, and a layer of vitreous insulating material between the conductor and support, and by which the conductor is attached edgewise to the support and in which the conductor is only partially. embedded, substantially as set forth.

conductor is only pant-ially embedded, sub

stantially as set forth.

'11. The combination of a reflexed ribbonlike conductor, a metal supporting-body, and a layer of adhesive insulating material between the. conductor and support, and by which the conductor is attached to the support and in which the conductor is only partially embedded, substantially as set forth.

12. The combination of a reflexed ribbonlike conductor, and a metal supporting-body, and a layer of vitreous insulating material between the conductor and support, and by which the conductor is attached to the suport and in which the conductor is only parially embedded, substantially as set forth.

13. The combination of a reflexed' ribbon like conductor, a supporting-body and a layer of adhesive material by which the conductor is attached edgewise to the support andin which the conductor is only partially em bedded, substantially as set forth.

- 14. The combination of a reflexed ribbonlike conductor, a supporting-body and alayer of Vitreous material by which the conductor is-attached edgewise to the support and in which the conductor is only partially embedded, substantially asset forth.

15. The combination of a reflexed ribbonlike conductor, a metal supporting-body, and a layer of adhesive insulating material between the conductor and support, and by which the conductor is attached edgewise to the support and in which the conductor is only partially embedded, substantially as set forth.

16. The combination of a reflexed ribbonlike conductor, and a metal supporting-body, and a layer of vitreous insulating material between the conductor and support, by which the conductor is attached edgewise to the support and in which the conductor is only partially embedded, substantially as set forth.

. 17. The combination of a ribbon-like con-' ductor, two plates between which the conductor is disposed edgewise, and a layer of adhesive material on each plate in which the conductor is partially embedded and by which the conductor is attatched t0 the plates, sub:

stantially as set forth.

This specification signed and witnessed this 2 5 

